Document No: LT0255 F3200/NDU AS4428.1 Installation Manual
Applications
Issue 1.04 30 June 2004 Page 6-31
6.4.3.4 4 TERMINAL ISOLATED REPEATER ALONE
When all the detectors on the IS circuit will generate a short circuit alarm condition it is
possible to use the lower-cost, 4-terminal isolating repeater without a ZAU401. This is
shown in Fig 6.4.3.4.
The following 4-terminal isolating repeaters can be used. (Note that dual channel repeaters
have two separate repeaters, and can connect two circuits to the panel).
Pepperl & Fuchs KHD0-ICS/Ex 1.51 (single channel)
Pepperl & Fuchs KHD0-ICS/Ex 2.51 (dual channel)
Pepperl & Fuchs KFD0-CS-Ex 1.51P (single channel)
Pepperl & Fuchs KFD0-CS-Ex 2.51P (dual channel)
Measurement Technology Ltd MTL5061 (dual channel)
FIG 6.4.3.4
SHORT-CIRCUITING DETECTORS WITH 4 TERMINAL REPEATER
Programming & Limitations
The required EOL resistance is lower than the standard 2k7. Two methods for obtaining the
correct EOL value are:
1. Place a 22K 5% resistor in parallel with the supplied 2k7 EOL. This achieves the
required value.
2. Or just use a 2k2 5% resistor as the EOL.
The circuit should be programmed as Mode 1, B3 as Normal, and B1 should be programmed
as Fault.
There can be no differentiation between short-circuiting MCP and detector operation on the
same circuit.
Detector quantity and circuit length limits are shown in Table 6.4.5.
SEE
TEXT
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